Nonlinear PID-like controllers for rigid-body attitude stabilization

Globally asymptotically 'stabilizing control laws are derived for rigid spacecraft attitude regulation. Two different approaches are introduced, one that seeks to derive a PID-like controller through a special Lyapunov function construction involving quadratic cross state weighting and the other via recursive passivation. Numerical simulations are performed to illustrate the performance of the two control laws. We show that the recursive passivation based controller (Controller #2) requires the knowledge of the inertia matrix for the controller implementation while the Lyapunov construction based controller (Controller #1) only needs the upper bound of the inertia matrix.